I think the basic structure should probably be something like this:
- Quick introduction of yourself. Basically go off of what Arcanist said. Do the "Hi my name is" stuff, do a solve to grab their attention, and explain that they too are capable of solving a cube.
- Explain some of your cubing backstory, and where you are now. I think here would be good to mention competitions. Talking about some prominent cubers like Max Park or Tymon Kolasiński would be good, but especially Yiheng Wang because of their age similarity.
- Encourage them to learn how to solve, and give a quick overview of the beginners method. Not exactly trying to teach them, but telling them how it works. Make sure you touch on what algorithms (and notation) are and when/how they're used. Give some resources at the end, make sure they have a way to reach out to you. Could be via email, phone, mail, etc.
Just go with your gut and write a quick script off of this. Be passionate and energetic. Talk TO them and not AT them.
Hope this helps, good luck!